The present invention relates to an electrical push-button switch, with built-in lamp, which allows one to clearly see the push-button.
More specifically, the invention refers to a switch of small dimensions of the type which comprises a tubular housing of dielectric material with an external threaded portion for fastening a nut onto a control panel of the apparatus in which the switch is to be incorporated. The tubular housing has, at one of its ends, a box or casing holding a button with a translucent cover. The button includes a pushing member in said tubular housing that acts on a microswitch, which, in turn, is mounted on a socket removably linked to the housing. The socket and a lamp remain held within the housing and the pushing member is biased by a spring toward a disconnecting position. In particular, the socket is for coupling small bulbs having no lampholder and having a tail on one end of a glass blister. Threads acting as terminals connect to the internal filament, these terminals are held by clamp-shaped connecting pins arranged in the interior of the socket of the switch, which grips the bulb tail.
Known embodiments of this kind of switch, such as the ones referred to in ES-A-U8600488 and in U.S. Pat. No. 4,871,890, are not appropriate for the construction of a miniaturized push-button switch, which is the object of this invention. In particular, they have a first drawback referring to locking on the control panel. Insertion of the switch through holes require the dismounting of at least the microswitch due to its large size. Also, replacment of the lamp bulb is a difficult operation.
A second drawback is the difficulty of holding inside a push-button of small size, and, in particular, of short length, a lampholder, the corresponding lamp, and microswitch.
A third drawback is the difficulty of handling the socket body to which the switch is attached, which demands one seize and handle the socket body by some pins designed to lock the microswitch, with risk of these pins being broken.